Whether you've concluded that you're not very smart or you've decided you're socially awkward, those beliefs will stick because of a psychological principle is known as &quotbelief perseverance.&quot

Once you believe something, whether it's a political belief or a belief about yourself, you'll filter out evidence to the contrary. Someone who believes they're stupid, for example, may chalk up a good grade on a test to luck or she may declare her success is a random fluke.

In addition, once you've developed a core belief, you'll pay close attention to any evidence that reinforces your belief. So if someone who believes she's stupid passes nine tests but fails one, she'll conclude the one failed test serves as further proof she's unintelligent (as opposed to thinking the nine successful tests may mean she's smart).

It isn't just beliefs about yourself; you're likely to cling to beliefs you hold about other people. For decades, studies have shown it takes more compelling evidence to change beliefs than it took to create them.